Instruments based on current broadband signal-generator architectures make use of switched filters along a transmission line in order to implement frequency-band filtering of the output, thereby extending the operating frequency bandwidth of a low-frequency signal generator (LFSG). Frequency-dependent radio-frequency (RF) switch limitations such as loss and limited frequency bandwidth begin to take their toll on signal-generator performance as an operating frequency range of an instrument implementing such current architectures extends into the millimeter-wave spectrum. Consequences can include a decrease in the dynamic range of the instrument, and a severe bound on the instrument's operating bandwidth.
There is a need for alternative architectures that extend an operating bandwidth of a signal generator while removing or reducing limitations imposed by the presence of switches along the transmission line.